Fuel system



A118 25 1959 R. J. POWELL ErAl. 2,901,031

FUEL SYSTEM 3 Sheets-Sheet 2 FUEL SYSTEM R. J. POWELL ETAL Aug. 25, 1959 Filed Feb. 1s, 1957 Allg. 25, 1959 R J, POWELL ETAL 2,901,031

FUEL SYSTEM s sheets-sheet 5' Filed Ffeb. 13, 1957 United States arent fice intrest Pelhunted` Aug.. 25, 1959 FUEL SYSTEM Robert J. Powell; and'y .lames E. Champion, Muskegon, Michi, assignors to Continental. Motors Corporation, Detroit, Mich.,I a corporation of; Virginia Application February 13, 1957, Serial No. 640,044 15- Claims. (Cl'. 15S-36.4)

Our invention relates to internal combustion engines, andl more particularly to fuel` delivery systems` therefor and comprising a vapor separator.

The problems encountered when vapors. are permitted to circulate in a fuel delivery system are well known, par* ticularly the phenomenon of vapor lock caused by the expansion of vapors due to the heat of the internal com. bustion engine, and` preventing fuel from getting to the engine. In aircraft engines particularly this. condition may be extremely dangerous. Heretofore, the methods. and devices provided for separating and eliminating vapors from the fuel lines have` been, if successful at all, rather complicated and expensive. Further, the presen-ce of vapor in the fuel materially affects the fuel metering and makes it impossible to meter the fuel with a degree of `accuracy as required by aircraft engines. It will thus be readily appreciated that entrapped vapor in the fuel is` not desirable and it can result in very poor engine per-V formance.

An object of the present invention is to eliminate vapors from the fuel delivery system of an internal com-v bustion engine by providing a simplified centrifugal vapor separator upstream of the fuel pump.

Another object of the invention is to preventvapor lock` in engine fuel delivery systems by lconstructing'a cen-` trifuge chamber having the fuel inlet from the fuel tank and outlet to the fuel pump tangentially arranged to induce centrifugal vapor separating motion in the chamber.

A further object of the invention is to provide improved means for vapor separation` in fuel delivery systems by constructing a centrifugal separating chamber having a vapor outlet connected with a venturi in a fuel line returning to the fuel tank.

A still further object of the invention is, to improve fuel delivery systems by providing a compact, simplified pump, vapor separator, and relief valve assembly, and'` including an emergency bypass system operable :to insure vapor-free fuel delivery in the event of fuel pump failure.

A more complete understanding of our invention may be had by reference to the accompanying drawings illustrating a preferred embodiment of the invention in which like reference characters` refer to` like parts throughout the several views and in which- Fig. l is a diagrammatic representation of a preferred fuel system incorporating the invention.

Fig. 2 is a side elevational view of the fuel pump, Vapor separator, `and relief valve` `assembly embodied in the fuel system of Fig. l,

Fig. 3 is` an elevational view showing the left end of the assembly of Fig. 2,. i

Fig. 4 is an elevational View ofthe vapor separator with the cover removed `as `seen substantially from the line` 4-4 ofFig. 2.

Fig. 5 is a view of the` vapor separator partially in section as viewed` from the left side of Fig. 4.

Fig. 6` is a top View of the vapor separator of Figs. tand 5.

. Fig; 7'` is an elevational view of the vapor separator as 2 viewed. from the left side of Fig. 5 and substantially from thcline7-7 of Fig. 2.

Fig. 8 is an elevational view of the vapor separator as seeufnom.` the left side of Fig. 7.

Fig..` 9. is a cross-sectional view taken `substantially on -theline 9-9xof Fig- 4.`

Fig. l0 is a cross sectional. view taken substantially on theline ltl-ltlof Fig. 8. l l

Fig.. 1l is an inner view of the vapor `separator coyer partially in section, as seen substantially fro the` line- 1.1.-11` of Fig. 3, and

Fig. 12 is an elevational view of the cover as seen from the; night side of Fig. l1.

Referring to Fig. l, a fuel system is illustrated for an internal combustionengine` having anair induction sys-` ter-n 10 includingj'a throttlehvalve l1 and air intake manifold 12. The fuel system is preferably of the fuel injection type comprising a tank 13, a fuel pump, vapor separator, and relief valve assembly 1,4, a metering device 15 operable connected to the throttle valve 11 by any means for such as linkage 16, and a fuel distribution valve 117 for distributing; fuel to injectors 18.

The assembly 144', seen also as a unit in Figs. 2 and 3,A comprises a conventional fuel pumpl 25, avapor separa-tor 26 having a casing 27 and cover 27a, and a conventional pressure relief valve, 28;. The. pump 25, vapor Separator 26 and: reliefvalve 23- `are preferably assembled together byv bolts. 29. and the cover 27a; is; preferably secured toy the. vapor separator by `Screws 3.0.

An auxiliary fuel pump is preferably disposed in the fuel tank 1;,3 aswshown in Fig. 1 and is operable` to pump fuel through a `Conduit 32 or other conducting meansthrough a filter 33; to 'an inlet 34 in the vapor separator casing 27. The casing 27 is provided with a substantially vertically disposed cylindrical centrifuge chamber The inlet 34.,` is arranged to deliver fuel into the chamber 35 substantially tangentially with respect `to theichamber wall and ata point. near the upper end of the ehamber 35 as illustrated in Figs. 8 and 10. A fuel outlet passage 3.6. is provided in the` casing near thc. lower end 0f the. chamber 35, and is also arranged substantial-ly tangentallyr with respect` to the chamber Wall` as shown in Figs. 4, 5, 6 and 9.-; The outlet passage 36 opens on the face of the casing 27 which abuts the fuel pump. 25 andis arranged, to` connect with theintake thereof.

. 36, being tangentially arranged, induce a rotary motion to. the fuel passing through the chamber 35, causing a lcentrifugal force to separate the fuel andl vapor, the vapor tending to collect in the upper `central portion of the chamber 35 due to its lower density, and the fuel passing to the pump will then be vapor free.

A port 42 is provided in the face of the casing 37 which abuts the fuel pump and is `openly connected with the discharge side of the fuel pump 25. A vertical passage 43 extends through the casing from the port 42 to. the top face yon which the cover 27a is secured. A vertical passage 44 in the cover 27a Iseen in Figs. 11 `and` 12 communicates with the passage 43 and connects with a diagonal passage 45 extendingthrough the cover to 3.1.1 Outlet port 46. A jet pump `or jet syphon member 4'7 is-dispcsed in the passage 45 and is connected at a lower drawn from -the chamber 35 through the passage 48 11H0 the low pressure area `of the jet syphon member 47. F1161 and vapor then pass out the port 46 and through a conduit 49 or other conducting means to the fuel tank 13:. A check valve 50 is preferably disposed in the conduit 49 to prevent reverse flow Iof vapor when the pump 25 1s ino erative.

Apnother passage 55 extends from the port 42 laterally through the casing Z7 to the face rabutting lthe pressure relief valve 28, and communicat with the inlet thereof. A screw 56 or other device -adjustably mounted in the casing 27 extends into the passage 55 to provide an adjustable restricting orifice upstream of the relief valve 2 8. The outlet side of the relief valve 28 communicates with a port 5'7 on the abutting face -of the vapor separator 27. A vertical passage 53 extends from the port 57. to a slot 59 in the Upper face of the casing 27 leading tangentially into the chamber 35 as shown in Figs. 5, 6 and 7. Thus excess pressure fuel relieved through the relief valve 28 is returned to the inlet portion of the vapor separator.

The fuel metering device 15 preferably includes a mixture control valve 60 operable by conventional means to bypass fuel under certain conditions, particularly at higher altitudes. Such bypass fuel is conducted by any means such as a conduit 61 to a port 62 in the casing 27, and thence to the relief valve discharge passage 58, through which it is returned to the chamber 35 by means of the slot 59.

An emergency bypass passage 65 in the casing 27, as shown in Fig. 9, connects the chamber 35 with the port 42, and is closed by a spring loaded bypass valve element 66, as shown in Figs. 4 and 9. In case of failure of the pump 25, the auxiliary pump 31 in the fuel tank 13 Will continue to supply the vapor separator chamber 35, and due to decreased pressure in the pont 42, the bypass valve element 66 will open, permitting fuel to ow directly from the chamber 35 into the delivery conduit 41, bypassing the pump 25.

If desired, as yan aid in the operation of the vapor separator 26, a baffle element '70 may be supported in the centrifuge chamber 35 by means of a stem 7l screwed into the lower end wall of the chamber 35, all as illustrated in Figs. 4, 6 and 9. Fuel entering the chamber 35 through the port 34 and the slot 59, both disposed above the baffle '70, will be defoamed in passing over and around the peripheral edge or rim `of the baffle 70 to the fuel outlet 36.

Although We have described but one preferred embodiment of our invention, it will be apparent to one skilled in the art to which the invention pertains that various changes and modifications may be made therein without departing from the spirit of the invention or the scope of the appended claims.

We claim:

l. In a fuel delivery system for an internal combustion engine, a fuel tank, a fuel pump for pumping fuel from said tank to said engine and having a capacity in excess of the fuel requirements of the engine, a fuel metering means for metering fuel to said engine, fuel conducting means connecting the intake side of said pump and said tank, a vapor separator disposed in said conducting means upstream of said pump and comprising a casing having a centrifuge chamber, a fuel inlet, a fuel outlet, a vapor outlet, and means inducing a substantially rotary motion to fuel in said chamber to centrifugally separate relatively light weight vapor and heavier weight fuel, a second fuel conducting means directly connecting the outlet side of said pump with said fuel tank to return excess fuel under pressure to said fuel tank, said Vapor outlet connected with said second conducting means, and means reducing pressure at the junction of said vapor outlet with said second conducting means to a value below the pressure in said chamber, said last means being thereby 4 operable to extract vapor from said chamber into said second conducting means.

2. In a fuel delivery systemffor an internal combustion engine, a fuel tank, a fuel pump for pumping fuel from said tank to said engine and having a capacity in excess of the fuel requirements of the engine, a fuel metering means for metering fuel to said engine, fuel conducting means connecting the intake side of said pump and said tank, a vapor separator disposed in said conducting means upstream of said pump and comprising a casing having a substantially vertically extending cylindrical centrifuge chamber, a fuel inlet and fuel outlet each arranged to induce a substantially rotary motion to fuel around the vertical axis of said chamber whereby to centrifugally separate relatively light weight vapor and heavier weight fuel, a vapor outlet located substantially on the vertical axis aforesaid, a second fuel conducting means directly connecting the outlet side of said pump with said fuel tank to return excess fuel under pressure to said fuel tank, said vapor outlet connected with said second conducting meafns, and means reducing pressure at the junction of said vapor `outlet with said second conducting means to a value below the pressure in said chamber, said last means being thereby operable to extract vapor from said chamber into said second conducting means.

3. ln a fuel delivery system for an internal combustion engine, a fuel tank, a fuel pump for pumping fuel from said tank to said engine and having a capacity in excess of the fuel requirements of the engine, a fuel metering means for metering fuel to said engine, fuel conducting means connecting the intake side of said pump and said tank, a vapor separator disposed in said conducting means upstream of said pump and comprising a casing having a substantially vertically extending cylindrical centrifuge chamber, a fuel inlet and fuel outlet each arranged substantially tangentially with respect to the side wall of said chamber to induce a substantially rotary motion to fuel around the vertical axis of said chamber whereby to centrifugally separate relatively light weight vapor and heavier Weight fuel, a vapor outlet located substantially on the vertical axis aforesaid, a second fuel conducting means directly connecting the outlet side of said pump with said fuel tank to return excess fuel under pressure to said fuel tank, said vapor outlet connected with said second conducting means, and means reducing pressure at the junction of said vapor outlet with said second conducting means to a value below the pressure in said chamber, said last means being thereby operable to extract vapor from said chamber into said second conducting means.

4. In a fuel delivery system for an internal combustion engine, a fuel tank, a fuel pump for pumping fuel from said tank to said engine and having a capacity in excess of the fuel requirements of the engine, a fuel metering means for metering fuel to said engine, fuel conducting means connecting the intake side of said pump and said tank, a vapor separator disposed in said conducting means upstream of said pump and comprising a casing having a substantially vertically extending cylindrical centrifuge chamber, a fuel inlet and fuel outlet each arranged substantially tangentially with respect to the side wall of said chamber to induce a substantially rotary motion to fuel around the vertical axis of said chamber whereby to centrifugally separate relatively light weight vapor and heavier weight fuel, said casing having a vapor outlet located substantially on the vertical axis aforesaid, a second fuel conducting means directly connecting the outlet side of said pump with said fuel tank to return excess fuel under pressure to said fuel tank, said vapor outlet connected with said second conducting means, and means reducing pressure at the junction of said vapor outlet with said second conducting means to a value below the pressure in said chamber, said last means being thereby operable to extract vapor from said chamber into said second conducting means, said vapor outlet disposed in a 'higher position thansaid fuel outlet, and said fuel inlet .disposed intermediate said vapor outlet .and said `fuel outlet.

5. In a fuel delivery system for an internal combustion engine, a fuel tank having a supply outlet and a return inlet, a fuel pumpyhaving an intake and a delivery outlet, a fuel metering means for metering fuel `to said engine, `fuel conducting means connecting said `tank supply out'- let` and said pump intake, a second fuel conducting means connecting said pump delivery outlet and said fuel metering means, and a `third fuel conducting means connecting said secondconducting means and said tank return inlet to return under pressure to said tank the portion of the fuel in excess of that required by said engine, a vapor separator disposed in said first conducting means and .comprising `a ,casing `having a centrifuge chamber, a fuel inlet, a fuel outlet, and a vapor outlet, means inducing a substantially rotany motion to fuel in said chamber to ,centrifugally lseparate `relatively light weight vapor and heavier weight fuel, said third conducting means including a jet syphon and said vapor outlet connected to said `jet syphon and arranged for extracting vapor from` said chamber into the third conducting means,

6. Ina fuel delivery system for aninternal combustion engine, afuel tank, a fuel pump for pumping fuel from said tank `to said engine, fuel conducting means connecting said pump and said tank, a vapor separator disposed in said conducting means and comprising a casing having .a substantially vertically extending cylindrical centrifuge chamber provided with a top and a bottom end wall, a fuel inlet and fuel outlet each arranged substantially tan- .gentially with respect to the side Wall of said chamber to induce a substantially rotary motion to fuel around the `vertical axis of said chamber whereby to centrifugally -separate relatively light weight vapor from heavier Weight fuel, said top end Wall having a vapor outlet located on the vertical axis of the aforesaid chamber, said pump having a fuel delivery outlet for delivering fuel to said engine, said casing having a passage openly `connected with said pump fuel delivery outlet and with said fuel :tank for returning to said fuel tank a portion of the fuel in excess of that `required `by said engine, said passage including a jet syphon connected with said vapor outlet and 'arranged to extract yvapor from said chamber into said passage for return to said tank.

7. In a fuel delivery system for an internal combustion engine, `a fuel tank, a fuel pump for pumping fuel from said tank to said engine, fuel .conducting means connecting said pump and said tank, a vapor separator disposed in said conducting means and comprising a casing having a substantially vertically extending cylindrical centrifuge chamber' provided with a top and a bottom end Wall, a fuelinlet .and fueloutlet each arranged substantially `tangentially with respect to the side wall of ,said chamber to induce a substantially rotary motion to fuel around the vertical axis of said chamber whereby `to centrifugally separate relatively light Weight vapor `from heavier Weightfuel, said fuel inlet disposed near the top end Wall and `said fuel outlet disposed near the bottom end wall of said chamber, said top end wall havingya vapor outlet located substantially on the `vertical axis of the aforesaid chamber, said pump having a fuel delivery outlet for delivering fuel to said engine, said casing having a passage openly connected with said pump fuel delivery outlet and with said fuel tank for returning to said fuel tank a portion of the fuel in excess of that required by said engine, said passage including a jet syphon connected with said vapor outlet and arranged to extract vapor from said chamber into said passage for return to said tank.

8. In a fuel delivery system for an internal combustion engine, a fuel tank, a fuel pump for pumping fuel from said tank to said engine, fuel conducting means connecting said pump and said tank and having a fuel intake in said tank, a vapor separator disposed in said conducting means intermediate said pump and said intakeand comprisinga ,casinghavingacentrifuge chamber, a fuel inlet, Aa fuel outlet, ,and a vapor outlet, means inducing a substantially rotary motion to fuel in said chamber to centrifugally separate relatively light weight vapor and heavier weight fuel, and means exhausting vapor from said chamber through said Vapor outlet, an auxiliary fuel pump connected with said conducting means intermediate said vapor separator and said `tank fuel intake, and an emergency bypass means comprising means openlyA Vconecting said chamber with saidengine and including a bypass check valve operable to open upon failure o f said first fuel pump for supplying said engine Withemergency fuel `from said auxiliary fuelpump through said centrifuge chamber.

9. .In a fuel delivery system for an internal combustion engine, a fuel tank, a fuel pump for pumping fuel from said tank to said engine, fuel conducting means connecting said pump and saidtank and having a fuel intake in said tank, a vapor separator disposed in said conducting means intermediate said pump and said intake and comprising a casing having a substantially vertically extending cylindrical centrifuge chamber provided with a top and a bottom end Wall, a fuel inlet and fuel outlet each arranged substantially,tangentially with respect to the side wall of said chamber to induce a substantially rotary motion to fuel around the vertical axis of said chamber whereby to centrifugally separate relative-ly light Weight vapor from heavier weight fuel, said top end Wall having a vapor outlet located substantially on the vertical axis of the aforesaid chamber, said pump having a `fuel delivery outlet for delivering fuel to said engine, said casing having ,a passage openly connected with said pump fuel delivery outlet and said fuel tank for returning to said fuel `tank a portion of the fuel in excess of that required by said engine, said passage ,including a jet syphon connected `with said vapor outlet and arranged to kextract vapor `from said chamber into said passage for return to saidtank, an auxiliary fuel pump connected with .said .conducting means intermediate said vapor separator and said `tank fuel intake, and `an emergency bypass means comprising meansopenly `connecting said chamber with said `fuel deliveny `outlet and including a. bypass check valve operable to open upon failure of said first fuel pump for supplying said engine With emergency -fuel `from said auxiliary fuel pump through said centrifuge chamber.

l0. In a fuel delivery system for an internal combustion engine, a fuel tank, a fuel pump for pumping fuelfrom said tank to said engine, fuel conducting means connecting 4said pump and said tank, a .vapor separator disposed in said conducting means and comprising a casing having a `substantially `vertically extending cylindrical .centrifuge chamber provided with a top and bottom end Wall, Aa fuel inlet and fuel outlet each arranged substantially tangentially with respect to the side Wall of Vsaid ,chamber to induce `a substantially rotary motion to fuel `around the `vertical axis of saidchamber whereby to centrifugally separate relatively `light Weight vapor from heavier weight fuel, said top end wall having arvapor foutlet located in said top end wall and .substantially` on the vertical axis of the aforesaid chamber, said pump having a fuel delivery outlet for delivering fuel to said engine, said casing having a passage openly connected with said pump fuel delivery outlet and with said fuel tank for returning to said fuel tank a portion of the fuel in excess of that required by said engine, said passage including a jet syphon connected with said vapor outlet and arranged to extract vapor from said chamber into said passage for return to said tank, and a pressure relief valve connected with said fuel delivery outlet and having a relief outlet openly communicating with said centrifuge chamber.

ll. ln a fuel delivery system for an internal combustion engine, a fuel tank, a fuel pump for pumping fuel from said tank to said engine, fuel conducting means connecting said pump amd said tank, a vapor separator disposed in said conducting means and comprising a casing having a substantially vertically extending cylindrical centrifuge chamber provided with a top and bottom end wall, a fuel inlet and fuel outlet each arranged substantially tangentially with respect to the side wall of said chamber to induce a substantially rotary motion to fuel around the vertical axis of said chamber whereby to centrifugally separate relatively light weight vapor from heavier weight fuel, said top end wall having a vapor outlet located substantially on the vertical axis of the aforesaid chamber, said pump having a fuel delivery outlet for delivering fuel to said engine, said casing having a passage openly connected with said pump fuel delivery outlet and with said fuel tank for returning to said fuel tank a portion of the fuel in excess of that required by said engine, said passage including a jet syphon connected with said vapor outlet and arranged to extract vapor from said chamber into said passage for return to said tank, said casing having a second passage open to said centrifuge chamber near the top end wall thereof, and a pressure relief valve connected between said fuel delivery outlet and said second passage.

12. In a fuel delivery system for an internal combustion engine, a fuel tank, a fuel pump for pumping fuel from said tank to said engine, fuel conducting means connecting said pump and said tank, a vapor separator disposed in said conducting means and comprising a casing having a substantially vertically extending cylindrical centrifuge chamber provided with a top and a bottom end wall, a fuel inlet and fuel outlet each arranged substantially ta-ngentially with respect to the side wall of said chamber to induce a substantially rotary motion to fuel around the vertical axis of said chamber whereby to centrifugally separate relatively light weight vapor from heavier weight fuel, said fuel inlet disposed near the top end wall and said fuel outlet disposed near the bottom end wall of said chamber, said top end wall having a vapor outlet located substantially on the vertical axis of the aforesaid chamber, said pump having a fuel delivery outlet for delivering fuel to said engine, said casing having a passage openly connected with said pump fuel delivery outlet and said fuel tank for returning to said fuel tank a portion of the fuel in excess of that required by said engine, said passage including a jet syphon connected with vapor outlet and arranged to extract vapor from said chamber into said passage for return to said tank, and means disposed intermediate said fuel inlet and said fuel outlet and constructed to defoam the fuel prior to discharge to said pump and to aid in separating the vapor from the fuel.

13. In a fuel delivery system for an internal combustion engine, a fuel tank having a supply outlet and a return inlet, a fuel pump having a capacity in excess of the fuel requirements of the engine and provided with an intake and a delivery outlet, a fuel metering means for metering fuel to said engine, fuel conducting means connecting said tank supply outlet and said pump intake, a second fuel conducting means connecting said pump delivery outlet and said fuel metering means, and a third fuel conducting means connecting said second conducting means and said tank return inlet to return under pressure to said fuel tank a portion of the fuel in excess of that required by said engine, a vapor separator connected in series with said first conducting means and having a vapor outlet, said vapor outlet connected with said third conducting means and means reducing pressure at the junction of said vapor outlet with said third conducting means to a value below the pressure in said chamber, said last means being thereby operable to extract vapor from said chamber into said third conducting means.

14. in a fuel delivery system for an internal combustion engine, a fuel tank having a supply outlet and a return inlet, a fuel pump having an intake and a delivery outlet, a fuel metering means for metering fuel to said engine, fuel conducting means connecting said tank supply Outlet and said pump intake, `a second fuel conducting means connecting said pump delivery outlet and said fuel metering means, and a third fuel conducting means connecting said second conducting means and said tank return under pressure to said fuel tank inlet to return a portion of the fuel in excess of that required by said engine, said third conducting means having a jet syphon passage, a vapor separator connected in series with said first conducting means and having a vapor outlet connected with the jet syphon passage in said third conducting means, whereby fuel iiow in said jet syphon passage is operable to extract vapor from said separator.

15. ln a fuel delivery system for Ian internal combustion engine, a fuel tank `having a supply outlet and a return inlet, a fuel pump having an intake and a delivery outlet, a fuel metering means for metering fuel to said engine, fuel conducting means connecting said tank supply outlet and said pump intake, a second fuel conducting means connecting said pump delivery outlet and said fuel metering means, and a third fuel conducting means connecting said second conducting means and said tank return inlet to return under pressure to said fuel tank a portion of the fuel in excess of that required by said engine, a vapor eparator disposed in said first conducting means and comprising a casing having a centrifuge chamber, a fuel inlet, a fuel outlet, a vapor outlet, and means inducing a substantially rotary motion to fuel in said chamber to centrifugally separate relatively light weight vapor and heavier weight fuel, said third conducting means including a jet syphon and said vapor outlet being connected to said jet syphon and arranged for extracting vapor from said chamber into the third conducting means.

References Cited in the file of this patent UNlTED STATES PATENTS 2,323,525 Ebel et al. July 6, 1943 2,521,270 Vanni Sept. 5, 1950 2,660,232 Noon et al. Nov. 24, 1953 2,669,838 Lee Feb. 23, 1954 2,688,925 Thoren et al. Sept. 14, 1954 2,734,729 Loftin Feb. 14, 1956 FOREIGN PATENTS 508,342 Great Britain June 29, 1939 "A Fri 

